Coil for dynamo-electric machines.



PATENTED JULY 21, 1903.

H. F. T. ERBEN. COIL FOR DYNAMO ELECTRIC MACHINES.

AI PLICATION FILED APR. 19, 1902.

Inve'n tor. Hermann F. T Erben.

N0 MODEL.

wLtnesses,

UNITED STATES Patented .I'uly 21, 1901s.

PATENT OFFICE.

HERMANN F. T. ERBEN, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

COIL- FOR DYNAMOe-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent N 0. 734,310, dated July21, 1903.

Application filed April is, 1902;

T 0 all whom it may concern:

Be itknown that I, HERMANN F. T.ERBEN, a citizen of the United States,residing at Schenectady, county of Schenectady, State ofNew York, haveinvented certain new and useful Improvements in Coils forDynamo-Electric Machines, of which the following is a specification.

This invention relates to a method of mak-. ing heavy field-coil s fordynamo-electric machines, such as the series coils for compoundwoundmotors and generators. The coil which is produced consists of aplurality of parallel layers of a flat copper conductor wound edgewise,the layers making one or more turns, as determined by the design of themachine, and connected in series or in parallel, as the case demands. Ifconnected in parallel, the coil is, in effect,the same as a solid barhaving the same cross-section as the combined lay-- ers; but it has beenfound that the mechanicaldifficulties involved in winding a solid bar oflarge cross-section practically prohibits such a construction. Inwinding acoil composed of a plurality of parallel strips of small sizethe several strips might be wound simultaneously, each being run throughits own tension device; but for large coils this is impracticable, owingto the difficulty of obtaining a winding-machine sufficiently strong tobend all at once the full section of copper. My invention obviates thistrouble, permitting the several layers to be wound successively.

The invention consists in forming the requisite number of convolutionsor layers of metal separately, assembling them side by side in parallelrelation, and securing their adjacent ends to suitable terminals. Iprefer to use a flat-sided conductor, such as a flat strip, ofconsiderably greater width than thickness and of even dimensionsthroughout. To form the separate convolutions, I prefer to wind such astrip edgewise into a helical coil of a large number of turns, then cutthe coil into lengths, and then interweave the lengths by screwing themtogether until they all lie parallel with their ends flush. The ends ofthe layers are then soldered together and to a terminal of propercross-sec- Serial to. 103,698. on lilotlel.)

tion. If a greater cross-section of coil is desired, a second coil ofsmaller or greater diameter can be similarly constructed and slippedinside or outside of the other, the terminals of the two being connectedin parallel.

In the accompanying drawings, Figure l is a diagrammatic View showing afiat conductor coiled into a helix. Fig. 2 is a perspective viewillustrating my invention and showing three layers of the coil, two ofthem being partly interwoven. Fig. 3 is a perspective view of a coilmade by my method. Fig. 4 is a diametrical cross-section of the same.

In carrying out my process a conductor 1, preferably a fiat-sided stripof copper, is wound edgewise on a suitable former 2 into a long helix,which is preferably, though not necessarily, cylindrical. The numberofconvolutions in the helix is determined by the number of parallel layerswhich will compose the finished coil and the number of turns each layerwill have. Thus if the coil is to have seven layers and each layer is tomake two and a half turns, as shown in Fig.3, the helix will be woundwith seventeen and a half turns. The helix is then cut into sevenlengths 3 of two and a half turns each, and the several lengths are theninterwoven, as indicated in Fig. 2, one after another being screwed intoparallelism with the others until their ends are all flush. If theseveral layers are to beconnectedin series,they mustbe insulated fromeach other and properly connected at the ends; but if, as is mostlikely, they are to be all in parallel the ends will all be solderedtogether and to a heavy terminal 4: of equivalent cross-section to themultiple coil. If desired, the several turns may be separated byspace-blocks 6 to insure good ventilation, though as a rule the heavycopper of which the coils are made is stiff enough to maintain thespaces between the turns without any separators. In addition to thespaces between the turns there is more or less of a circulation of airbetween the layers, so that the coil is easily kept cool. To increasethe cross-section of the coil without using a wider strip or morelayers, a second coil 7 may be made in the same Way and slipped insideor outside of the first coil, the

terminals of the two coils being united to place them in parallel. Ifthe finished coil is to have only'one turn, the requisite number ofconvoiutions or layers are readily assembled side by side in parallelrelation with outscrewing them together.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. The method of making a coil for a dynamo-electric machine, whichconsists in assembling side by side a plurality of separate layers of aflat conductor, and connecting their adjacent ends to a suitableterminal.

2. The method of making a coil for a dynamo-electric machine, whichconsists in forming a plurality of convolutions of metal, assemblingthem side by side, and connecting their adjacent ends.

3. The method of making a coil for a dynamo electric machine, whichconsists in forming a plurality of flat helical convolutions of metal,assembling them in close parallel relation, and providing their adjacentends with terminals.

4. The method of making a coil for a dynamo electric machine, whichconsists in winding aconductor intoahelix, cuttingsaid qsaeio helix intolengths, and assembling said lengths.

5. The method of making a coil -for a dynamoelectric machine, whichconsists in winding a fiat-sided conductor into a helix, cutting saidhelix into lengths, and interweaving said lengths.

6. The method of making a coil for a dynamo-electric machine, whichconsists in Winding a flat conductor edgewise into a helix, cutting saidhelix into lengths, and inter- Weaving said lengths.

7. The method of making a coil for a dynamo electric machine, whichconsists in forming two sets of helical lengths of a conductor, ofdifferent diameters, interweaving similar lengths so as to form twocoil-sections of different diameters, placing one inside the other, andconnecting the adjacent ends of said sections.

In witness whereof I have hereunto set my hand this 17th day of April,1902.

HERMANN F. T. ERBEN.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

